CIRCUIT FOR GENERATING HARMONIC AND OPERATING APPARATUS FOR LED INCLUDING THE SAME

摘要

PURPOSE: A harmonic producing circuit and an LED drive unit are provided to extend the product life of a bulk capacitor by the replacement of an electrolytic capacitor with a film capacitor with a low capacity. CONSTITUTION: A voltage sensing unit(210) functions as a sensor by being supplied with the voltage of an input power source. A comparator(220) converts the signal of the input power source sensed by the voltage sensing unit into a square waver. A harmonic producer(230) plays a role in launching the harmonic wave with synchronization harmonized with the input power source. A band pass filter(240) changes the harmonic wave with the form of a square wave launched from the harmonic producer into a sinusoidal wave. An adder(250) plays a role in combining the elementary wave of the input power source sensed by the voltage sensing unit with the sinusoidal wave output from the band pass filter. A rectifier(260) plays a role in rectifying the wave form output from the adder. A power factor correction circuit(270) plays a role in controlling the form of the input current. [Reference numerals] (210) Voltage sensing unit; (220) Comparator; (230) Harmonic producer; (260) Rectifier; (270) Power factor correction circuit; (310) EMI filter